All Systems Go for Final Shuttle Mission to Hubble Space Telescope

The countdown for the fifth and final service trip to the Hubble Space Telescope begins May 8 with the space shuttle Atlantis scheduled for a May 11 launch from the Kennedy Space Center. The final voyage aims to repair failing instruments and install a new camera and spectrograph that should extend the life of Hubble by five years.

NASA said May 8 all systems are go for a May 11 manned mission to the Hubble Space Telescope. The
deployment of Atlantis to the Hubble -- which is in desperate need of
repairs -- represents the space shuttle's fifth and final trip to the space telescope before the fleet is retired in late 2010.

The seven-man crew will conduct five spacewalks to install two new instruments, repair two inactive ones and perform component
replacements over the 11-day mission to keep Hubble operational through at least 2014.

In addition to the scheduled repairs, Atlantis will also carry a replacement Science Instrument Command and Data
Handling Unit for Hubble. Hubble's current system stopped working on Sept. 27, 2008,
delaying the servicing mission until the replacement was ready.

"All of the systems are in great shape," reported NASA Test Director
Jeremy Graeber during a countdown status briefing at
the Kennedy Space Center. "Launch countdown preps are complete and we don't have any
issues to report right now."

Shuttle Weather Officer Kathy Winters said there was only a 20 percent chance that weather could cause issues at
the preferred launch time of 2:01 p.m. EDT May 11. The team has a
May 11 launch window of about one hour that opens 20 minutes earlier at 1:41
p.m. The mission has a three-day window for launch before having to delay until May 22 due to a conflict with a military launch.

Launch procedures get underway May 11
with personnel taking their places at 3:30 p.m. By 4 p.m., the
countdown will begin, ticking backward from T-43 hours. At the launch pad, Atlantis'
payload bay doors will be closed.

NASA describes the flight as a "mission to once more push the boundaries of how deep in space
and far back in time humanity can see. It's a flight to again upgrade
what already may be the most significant satellite ever launched."

Altman added, "Hubble puts cutting edge science together with a visual image that
grabs the public's imagination. I think that's the first
step in exploration. Because Hubble takes light that's been traveling
for billions of years, sucks it in and shows it to us. It's like taking
you on a journey 13 and a half billion light years away while you sit
there at home and look out at the universe."

The astronauts' primary focus on the
voyage will be to replace Hubble's Wide Field and Planetary Camera with
a newer, more powerful model and to install a new spectrograph, an
instrument that breaks light into its component
colors, revealing information about the objects emitting the light. The
Cosmic Origins Spectrograph sees exclusively in ultraviolet light and
will improve Hubble's
ultraviolet sensitivity at least 10 times, and up to 70 times when
observing extremely faint objects.

The new wide field camera will allow
Hubble to take large-scale, extremely clear and detailed pictures over
a very wide range of colors.The new camera and spectrograph will complement the
scientific instruments already on the telescope, in particular the workhorse
Advanced Camera for Surveys and the Space Telescope Imaging
Spectrograph.

The repair work and the installation
will require a different type of spacewalk than astronauts encounter on
spacewalks at the International Space Station.

"It's more like brain surgery than construction," explained Lead Flight Director
Tony Ceccacci. "On station spacewalks, you're installing large
pieces of equipment - trusses, modules, etc. - and putting it together
like an erector set. You can't do that with Hubble. Hubble spacewalks
are comparable to standing at an operating table, doing very dexterous
work."